Galvanizing furnace



Nov. 1, 1960 K. FRITZ GALVANIZING FURNACE Filed April 15. 1958 v v v `v v vvvvv United States GALVANIZING FURNACE Karl Fritz, Feithstrasse 25, Hagen, Westphalia, Germany 'Filed Apr. 15, '1958, Ser. No. 728,593

Claims priority, application Germany Apr. 26, 1957 8 Claims. (Cl. 263-11) The present invention relates to -a galvanizing furnace for coating articles with metal.

It has been known to coat articles with metal by immersing or dipping the same into a bath of molten metal. For this purpose, galvanizing furnaces have been used comprising such baths. Conventional furnaces with metallic galvanizing pots heated from below have been replaced by furnaces with ceramic pots having heating means in their lids.

The known lid-heated ceramic pots are limited in their application in that they can be used for coating of tapes and wires only above certain minimum cross sections of said tapes or wires, as for instance thin wires may easily break and the re-insertion of fractured wires causes considerable difficulties. In order to re-introduce a fractured wire linto the bath, the lid of the furnace must necessarily be lifted, and this entails losses in time and production. For the galvanization of piece goods these conventional furnaces are not suitable.

It is an object of the present invention to provide a furnace with a lid-heated ceramic galvanizing pot which can be used for immersion-coating of articles with a metal, such as zinc, without limitation as to the size or cross-sectional shape of such articles.

It is fanother object of the invention to provide the lid of such a furnace with a protruding lower edge penetrating into the molten bath in a manner similar to a water seal, this lid covering the open side of the molten bath only partially, i.e., leaving a part of the bath surface uncovered. The ar-ticles to be coated can be introduced into the uncovered part of the bath without diiculty.

It is another object of this invention to provide a galvanizing furnace of the type referred to herein, wherein the lid is displaced towards one side of the pot, resulting in an asymmmetrical arrangement. Tests have proven that thin wires can be coated with a metal when such an asymmetrically arranged lid only partially covering the bath surface is used on the galvanizing pot. Another advantage of this kind of lid arrangement is that larger objects can be coated in this galvanizing pot, since they can be readily introduced into the uncovered part of the bath adjacent the lid for dipping. It is a further object of this invention to construct the galvanizing pot in such a way, that the bottom part thereof below the lid is elevated with respect to the remaining portion of the bottom, whereby the part below the lid slopes downwardly to the remaining bottom part. Thus, the bath below the lid is less deep than the uncovered part of the bath used for immersing. As a result of this, the total amount of molten metal actually used in the bath is kept at a minimum.

It is a still further object of this invention to provide the lid, above the lower protruding edge thereof, with flange-like extensions on two opposite sides, said extensions seating on the rim of the furnace at the respective two opposite sides so as to leave space between the lid and the rim at the other sides. The lid may be arranged centrally on the galvanizing furnace or pot, thus M 2,958,520 Patented Nov. l,` 1960 providing two equally uncovered yareas on the surface of the molten bath. In this case, the bottom of the pot will have two uniformly inclined bottom parts sloping downwardly from a central apex toward the sides. Due to this central arrangement of the lid on the galv'aniZing pot, seating only on two edges of the pot and leaving space at the two other sides for the immersion of the articles to be coated, a superior utilization of the heat supplied to the pot and, thereby, a high etlciency of the furnace are obtained, because the heat is utilized at both sides of the lid.

The new furnace of the present invention has a higher capacity, as it can be more easily changed than the known furnaces of this kind. If the depth of the pot part below the lid is less than at the sides, the efiiciency of the furnace is increased. In addition, when the metal in the pot is heated, the metal bath is agitated, due to the whirling action caused by the shape of the bottom. Thus, superior agitation is obtained if the bottom of the pot has a raised pontion in its center uniformly sloping toward two sides.

Still further objects Iand the entire scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

ln the drawings:

Figure l shows a cross section through a galvanizing furnace constructed in accordance with one form of the present invention;

Figure 2 illustrates a longitudinal section through t-he same furnace along the line 2-2 of Figure l;

Figure 3 is a cross section through a galvanizing furnace constructed in accordance with a second modification of this invention and illustrating a symmetrically arranged lid; and

Figure 4 shows a cross section through a galvanizing furnace constructed in accordance with a further embodiment of this invention.

The cross sections of the bath as illustrated in Figures 3 and 4 corresponds to the section shown in Figure l.

Referring in more detail to the drawings, in Figures 1 and 2 a furnace l comprising brick walls supports a galvanizing pot 20 adapted to receive a bath 2 of coating metal, particularly zinc, to be melted. Above the pot 20, there is provided a lid 3 which can be raised or lowered in a manner known per se, said lid extending over the entire length of the pot, while covering only partially the width of this pot. The bottom of this lid 3 is provided with a rim 3 protruding downwardly from the lid and adapted to penetrate the melt 2 to seal the heating chamber formed in the lid in a manner similar to a water seal.

As shown in Figure 1, the lid 3 is seated on the pot 20 covering only the right part thereof, i.e., the lid is displaced toward the right in such a way, that one of its longitudinal edges engages one longitudinal edge of the pot 20, thereby providing at the left an uncovered bath surface between the opposite longitudinal edge of this lid and the opposite longitudinal edge of the pot 20. The articles, such as wires, or tapes, ribbons or bands can be readily introduced into the bath through this uncovered surface of the pot 20 by means of the immersing device 4 so as to be immersed in the molten metal 2.

The immersing device consists of a cylinder immersing in the molten metal and under which the wires or bands are pulled through the bath.

Metallic piece goods can be readily introduced into the bath of pot 20 by means of containers, tongs etc., so as to be immersed in the molten metal 2.

In order to keep the necessary amount of molten metal 2 ata minimum'and, thereby, the heat requirements as low as possible, the bottom portion 5 of the pot 20 is inclined at the location below the lid 3, i.e., the bottom portion 5 slants downwardly from the right towards the main bottom portion.

kAs shown in Figure 2, the lid 3 is seated on the pot 20 with laterally protruding edges `6` resting on two opposite side edges and 11 of the pot 20.

In contr-ast to this, the lid 3 in the embodiment of Figure 3 is seated with its laterally protruding edge `6 only on two opposite side edges, such as 10 and 11 in Figure 2, of the galvanizing pot 20, while the other two side `vedges 12 and 13 of the pot 20, see Figure 3, are not engaged by the lid 3. Hence, areas Z and 2 of the upper surface `of the bath 2 to both sides of the lid 3 remain uncovered. The articles to be coated can be immersed in the bath 2 by introducing the same therein through the ,one or the other or both of these areas 2' and 2".

For lifting and lowering the lid 3, conventional means, as Vf or instance Vthe illustrated crank operated lifting devices 7, see Figure 2, may be used. The lid 3 is heated in the usual manner, for example, by means of electric resistance heating units or, as illustrated, by means of a gas fed into the chamber formed under the lid through nozzles 8. A ue 9 is provided to discharge the exhaust gases from the lid chamber.

While in the embodiment of Figure 3 the pot 20 has a flat bottom, the bottom of the pot in Figure 4 is Acentrally raised, i.e., the bottom of the pot is constructed so as to provide two at bottom portions 14 and 15 at the sides and two inclined portions 16 and 17 sloping upwardly towards a common edge 18 directly below the lid 3. 'Ihe center elevation of the bottom may be obtained by convex arching of the bottom portion below the lid 3, rather than with the use of several flat bottom portions.

The sides and bottoms of the pots 20 in Figures l to 4 are supported and protected by bricks 21 of refractory material.

I claim:

l. In a furnace with a galvanizing pot containing a 4 bath of molten metal for coating articles with said metal by immersing the same into said bath, a lid removably supported on said pot and forming a heating chamber above the liquid level of the bath, heating means in said lid, an endless edge protruding from the lower side of said lid and penetrating the surface of said bath around the entire perimeter of said heating chamber when said lid is resting on said pot, said lid being smaller than the top area of said pot so as only partially to cover said area, whereby when said lid is resting on said pot, said endless edge penetrates into the bath and constitutes a complete sealing means for sealing said heating chamber.

2. A furnace according to claim 1, wherein said lid is disposed to one side of said area, thus providing an asymmetrical arrangement with respect to the covered and uncovered pot areas.

3. A furnace according to claim l, wherein said pot has a bottom which is higher below the lid than below the uncovered portion of said area.

4. A furnace according to claim 3, wherein said bottom has a sloping portion below said lid.

5. A furnace according to claim l, wherein said pot has four side walls, said lid has a laterally extending edge above said downwardly protruding edge, said laterally extending edge seating on two opposite walls of said pot, while space remains between said lid and the other two walls of said pot.

6. A furnace according to claim 5, wherein said lid seats in the center of said pot, thus providing two equal uncovered areas on said bath.

7. A furnace according to claim 6, wherein the central portion of said bottom of said pot below said lid slants downwards to said two side portions from a centrally disposed apex which is higher than the two side portions of said bottom.

8. A furnace according to claim 1, wherein said bath contains molten zinc.

References Cited in the le of this patent vUNITED STATES PATENTS 1,500,651 Smith July 8, 1924 2,040,787 Frost May l2, 1936 2,074,115 Mader Mar. 16, 1 937 2,264,740 Brown Dec. a, V1941 2,738,180 Jerkas Mar. 13, 1956 Disclaimer 2,958,520.-K6WZ Fritz, Hagen, VVestphala, Germany. GALVANIZING FURNAGE. Patent dated NOV. l, 1960. Disclaimer filed Aug. 26, 1964, by the inventor. Hereby enters this disclaimer to claims l, 2, 3, 4 and 8 of said patent.

[Oycz'al Gczette November 17, 1.964.] 

